Electrical control network



May l, 1962 c. E, MATHls 3,032,686

ELECTRICAL CONTROL NETWORK Filed May 15, 1959 5 Sheets-Sheet l POWER SOURCE ELLE- E lo /lz B- PowER 6 ,so POWER ,eo 6.2 souRcE f( souRcE o/ /72 7| |04 /72b @Q04 *u2 28 f- |4 74 /73 @dos FFM l 666 |05 113 I T /74b i@ 30 ELE- E 4 LQMJ ,4o PowER /lz SOURCE lso 0/62 rfer A sa INVENTOR. 78 '6 a 2 cEcu. E. MATHls BY )ua M ATTORNEYS May l, 1962 c. E. MATHIS 3,032,686

ELECTRICAL CONTROL NETWORK Filed May 1s, 1959 5 sheets-sheet 2 EL-E7 -F'XXI INVEN TOR.

cEcll. E. MATHls BY )5W q MT May l, 1962 ELECTRICAL CONTROL NETWORK Filed May 13, 1959 3 Sheets-Sheet 3 INVENTOR.

cEclL E. MATHls ATTORNEYS c. E. MATHls 3,032,686

United States Patent lis, rnd.

Filed May 13, 1959, Ser. No. 812,892 Claims. (Cl. 315-189) The present invention relates to an electrical control network, and more particularly to a network having a plurality of electrically operable devices which may be energized respectively in particular discrete groups or combinations.

Display or read-out devices which include a bank or array of electric lamps are commonly used in connection with computers, athletic Scoreboards and the like. Control devices are used to energize the lamps in discrete groups or combinations which represent characters in the form of letters of the alphabet, numerals, symbols and the like, and such control devices which have been used in the past have included multi-contact circuit breakers, mechanical drum controllers, and permanently connected electronic circuits having no moving parts. Such electronic circuits involve the use of a control matrix wherein two sets of conductors are connected to each other by means of resistors arranged in the matrix according to a predetermined pattern. To one set of these conductors are connected a plurality of neon lamps or the like, these neon lamps constituting the display device above-mentioned. Byvenergizing a particular one of the other set of conductors, a particular group of the display lamps are energized for presenting a visual display of a desired character. y

Certain deficiencies reside in the permanently connected circuit just described, which include the conductive interconnection of all conductors with resistors whereby it is impossible to completely electrically isolate a selected display circuit from a non-selected circuit, this interconnection serving to limit the number of dilerent characters which may be displayed and also requiring that the neon lamps meet very critical specifications as to electrical operating characteristics.

The present invention constitutes a decided improvement over the electronic circuit (matrix) just described in that the energizing and display circuits are completely electrically isolated from each other, do not require neon lamps or similar electrically operable devices having critical operating characteristics, and can be used to display an almost infinitely large number of characters without limitation by merely enlarging the size of the matrix.

It is therefore an object of this invention to provide an improved electrical control network in which a larger number, than were heretofore possible, of electrically operable devices may be selectively energized in predetermined discrete groups or combinations.

It is another object of this invention to provide an electrical control network for displaying an almost unlimited number of characters in a form which is simple and compact, is completely dependable and operates at high speed, is economical in the original construction and operation'thereof, and, further, has no moving parts.

Other objects will become apparent as the description proceeds.

To the accomplishment of the above and related objects, my invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that specific change may be made in the specific constructions illustrated and described, so long as the scope of the appended claims is not violated.

In the drawings:

Y FlG. 1 is a partial schematic circuit diagram of one embodiment of this invention; FlG. 2 is a partial schematic diagram of another embodiment;

FIG. 3 is a similar diagram of still a diterent embodiment;

FIG. 4 is a diagram of yet another embodiment;

FIG. 5 is a front elevation of a bank of neon bulbs arranged in a display panel;

FIG. 6 is an illustration of the various types of characters which are capable of being presented on the display panel of FIG. 5; and

FIG. 7 is a partial schematic diagram of still another embodiment whereby informationmay be stored for a period of time.

Referring to the drawings, and more particularly to FIG. l, a' power supply 10 capable of delivering, for example, 275-volts D.C., is shown as being connected to a pair of supply lines 12 and 14.` The line 14 may be grounded as shown. Extending vertically in the drawing are a-lirst vseries of laterally spaced conductors, indicatedl by the reference numerals 16 through 26, respectively. Extending horizontally are asimilar set of spaced conductors 28 through 58, both of these veitical and horizontal conductors being insulated from each otherby n ot being connected, to generally constitute a matrix of conductors. As will appear from the following description, the matrix may be composed of as many conductorsas may be desired, depending upon the number of characters which are desired to be displayed by the panel of:

tronic switching devices as will appear fromthe following.v

To the second conductors 28 through 58 are connected a bank or series of gas diode indicators 72 through 102, respectively, these indicators in one embodiment of this invention being neon lamps. Connected in series between these gas diodes of neon lamps and the supply line 14 are a plurality of, current-limiting resistors, indicated by the reference numerals 71 through 101, respectively.

' Connected to each of the rst conductors 16 through 26, respectively, are a plurality of gas diodes (neon lamps) in character groups, there being one character group for each of the conductors 16 through 26, respectively. For example, the diodes 104 through 111 constitute the character group for the line 16, the diodes 112 through 119 constitute the character group for line 1S, the diodes 1120, through constitute the character group for line 2.0, and soon.

These group diodes are also connected to the second conductors 28 through 58, respectively, in accordance with a preselected pattern depending upon the characters which the' bank of neon lamp indicators 72 through 102 are selectively to display. For example, the remaining terminal of the diodes 104 through 111 are connected, respectively, to the lines 28, 30, 32, 40, 42, 44, 46 and 54. With respect to the group diodes for the line 18, these diodes are also connected to the lines 28, 30, 36, 40, 50, 54, 56 and 58. The group diodes for the other rst conductors are connected to the second conductors, as shown.

v. It will be noted that the group diodes constitute connections between the respective first and second conductors of the matrix, and as such they act as static-switches which function to switch energizing voltages from the rst conductors 16 through 26, respectively, to the respective second conductors 28 through 58. The term staticswitches is intended to dene an electrical or electronic switch having no moving parts, which consumes little power, and which presents a high impedance when the device is oi; in other words, is essentially open-circuited. Typical of such static switches is the neon lamp or gas diode; however, avalanche diodes or other electronic switching devices having similar switching charac, teristics as neon lamps may be used instead, as will appear obvious to a person skilled in the art.

In one embodiment of this invention, the neon lamps which serve as the gas diodes in FIG. 1 may be of the type identied by the number NIE-2H which require 135- volts to tire and 90-volts to maintain ionization. Other type numbers which may be used are the NEI-2, NE-ZE, NB-Sl, or any other type of gas glow diode; these gas diodes, unlike rectifying diodes, re responsive to application of a predetermined voltage of either polarity and thus provide a symmetrical switching characteristic thereby permitting operation of the system from an alternating current source.

Referring to FIG. 5, the display diodes 72 through 102 of FIG. 1 are lixedly arranged in a flat plane in accordance with the pattern shown so that when a particular diode is energized its `glow will illuminate a particular segment in the pattern. With this pattern, at least all of the characters indicated in FIG. 6 may be displayed by selectively energizing particular groups of the diodes 72 through 102, and in the following explanation the display of the letter A will be demonstrated. Considering FIGS. 1 and 5, closure of the switch 60 (with all of lthe remaining switches remaining open) will serve to apply the total voltage from the source 10 between the conductor 16 and the ground. In the example given, this means that 275- volts D.C. is applied to this line 16. This being true, 275-volts are applied to diode 104, diode 72 and resistor 71 in series. 'Ihis same voltage is applied to all of the other diodes connected to the line v16 and to the respective diodes of the display bank; for example, diode 105 being connected in series with diode 74 and resistor 73 between the two lines 12 and 14. Since these series-connected diodes each re at 13S-volts, it follows that the 275- volts applied thereto is sucient to iire both of the seriesconnected diodes. In other words, the diodes which fire in pairs are:

104-72 10S-86 105-74 109-88 106,-7 6 11G-.90, and 107-84 111-98 For convenience of explanation, only the two diodes 72-104 will now be considered.

YAfter tiring, the voltage drop across each of these tubes is 90volts. The total voltage drop across both is 180- volts. VThis means, therefore, that 95vo1ts is dropped across the resistor 7 1.

Since the voltage which appears across both the resistor 71 and diode72 actually constitutes a voltage source for the respective second conductor 28', it is seen that the two voltages appearing across both the resistor 71 and the diode 72 totalling 18S-volts are applied to line 28. This same 18S-volts appearing on the line 28 will now be applied to several of uthe remaining diodes connected to line 28. By tracing the various diode circuits from the conductor 28 to ground, it will be noted that one series circuitris composed of diodes 1-12, 114 and 80 in series with resistor 79 to ground. With only 185 volts available on the conductor- 28, those display diodes which are connected to the source through more than one diode will not lire, three times 135 volts (3 135), or 405 volts in other words, being required to lire these three diodes. Another series circuit is composed of diodes 112, 113 and 74 through resistor 73 to ground, but line 30 is also at 185- volts potential because, like diode 104, diode 105 is red; therefore, no potential diiference exists across the series arrangement of the diodes 112 and 113 and they remain open-circuited. In this manner, it can be seen that display diodes 72, 74, 76, 84, 86, 88, and 98 which are each connected to the source 10 through a single diode from line 16 will tire. Those display diodes 78, 80, 82, 92, 94, 96, and 102 which are each connected to the source 10 through two or more diodes will not re. In FIG. 5, these display diodes 72 through 102 are arranged as shown in a panel. Energizing the line 16 of FIG. 1 by closing switch 60, the diodes 72, 74, 76, 84, 86, 88, 90 and 98 will tire and all others will remain extinguished, thereby illuminating the respective segments of FIG. 5 while the others remain dark. The resultant display is the letter A having the coniiguration shown in FIG. 6.

The other rst conductors 18 through 26 are connected to the proper second conductors 28 through 58, respectively, through character groups of diodes as previously explained for displaying other letters, numbers, punctuation marks and the like. Thus, by closing any one of the various switches 60 through 7 0, a particular character display on the panel of FIG. 5 will be obtained.

Of importance is the fact that those display diodes 72 through 102 which are connected to the source 10 through more than one -other diode will not fire, since all of the remaining display diodes are series-connected in threes. Since three diodes requiring 13S-volts each to fire in series require a total of 40S-Volts, it is obvious that the 18S-volts appearing on the respective lines 28 through 5S is insufcient to cause firing of any of the display diodes serving as one of the three.

Referring to FIG. 2, it will be seen that the resistors and display diodes are interchanged in series. This is to villustrate the fact that the resistors serve their proper functions when connected on either side of the respective display diodes. In like manner, the circuit functions properly if the resistors are placed series with diodes 104, 105, 112, etc., or in series with switches 60, 62, 64, etc. FIG. 2 illustrates only a portion of FIG. l and uses the same reference numerals to indicate like parts.

An additional neon lamp may be added in series with each resistor-neon lamp 71-72, 73--74, 75-76, etc., for the purpose of obtaining additional illumination in the display and also to provide an additional switching effect. Thus, instead of only one lamp 72, 74, 76, 78, etc. for each line 28, 30, 32, 34, etc., respectively, there are two such lamps connected in series.

In FIG. 3, like numerals are used to indicate like parts in the circuit which is substantially identical to that of FIG. l with the exception of that explained in the following. The display diodes 72 through 102 have resistors connected in shunt therewith. For example, resistor 72a is shunt-connected across diode 72, 74a across diode 74, 76a across 76, and 78a across 78. In operation, assuming that the source 10 delivers only 230- volts D.C. instead of 275-volts D.C. as in the previous example, when switch 60 is closed diode 104. fires through resistors 71 and 72a. The potential across diode 104 thereupon drops to 90-volts, the voltage drop across resistor 71 is small, and the voltage drop across resistor 72a approaches 140-volts; this is more than suicient to re diode 72. This same ring sequence happens with the other display diodes 74 and 76. The voltage drop across diode 72 now reduces to 90-volts, the maintaining voltage, and the voltage drop across resistor 71 rises to 50-volts. It is thus seen that satisfactory operation is obtained with -a lower voltage power supply, this lower voltage being less than that required to fire two of the diodes connected in series.

In FIG. 4 is illustrated another embodiment of this invention wherein alternating current only is used as the power source. In this figure, like numerals again indicate like parts.

Instead of using diodes as the display devices, transformers indicated by the numerals 72b, 74b, etc., are used, the primaries of these transformers being connected in series with the respective horizontal lines 28, 30, etc. To the secondary windings of these transformers may be connected any suitable electrically operable device such as a lamp, solenoid or the like. Such lamps or solenoids may be arranged in a suitable display mechanism for providing either a temporary or permanent display record of the character being produced. Instead of using transformers, electroluminescent phosphor elements may be substituted, these elements glowing in response to the A.C. voltage applied thereto. In operation, the power source a typically supplies 165 to 230 volts A.C., R.M.S. The circuit functions in precisely the same manner as the circuits of the preceding embodiments, closure A of one of the switches 60 through '70 serving to energize a particular group of the transformers 72b, 74b, etc. The switching diodes 104, 105, 112, 113, etc. function in precisely the same manner in this embodiment of FIG. 4 as they do in the preceding embodiments. Thus, the present invention is not limited to a power supply of any particular voltage polarity and may be either alternating or unidirectional in character.

In FIG. 7 is Iillustrated still another embodiment of this invention which utilizes thyratrons for maintaining the display lamps 72, 74, 76, etc. energized. In this figure, like numerals indicate like parts. In series with the respective display lamps 72, 74, 76, etc. are respective resistors 72C, 74C, 76C, etc. Across these resistors are connected the control grid 144 and cathode 145 of thyratrons 146, 147 and 148, respectively. To the anodes of these thyratrons is connected a source of D.C. voltage of a magnitude sutlicient to fire the thyratrons only when the voltage on the grids thereof rises to a predetermined positive value. Current limiting resistors 72d, 74d, and 76d Iare series connected between the diodes 72, 74, and 76, respectively, for limiting currents through the diodes to safe values.

In operation, when the voltage drop across the respective resistors 72C, 74C, 76C biases the control grid sufficiently to re the thyratron, a circuit is established through the thyratron and the respective display lamp for maintaining the latter glowing. The lamp will thus glow until the thyratron is switched off. By this means, any selected display may be stored for an indefinite period of time regardless of the duration ofclosure of the energizing switches 60, 62, 64, etc., the supply voltage applied to the thyratrons being suflicient to fire andmaintain fired both the thyratron and the display lamp in series upon the application of a firing bias to the control grid.

In a typical operating embodiment of this invention, as illustrated in FIG. 1, with the display lamps arranged as shown in FIG. 5, typical values for the component parts are as follows:

Resistors 71 through 14H-33,000 ohms.

Diodes 72 through 102 and 1434 through 14S-Type No.

Nia-2H.

Power source 10-195-vo1ts A.C. R.M.S. or 275-volts In the embodiment of FIG. 3, the typical value for the resistors 72a, 74a, 76a, 78a, etc. is 1megohm.

The values of the component parts are not critical. This is especially true of the operating characteristics of the gas diodes. These characteristics may vary widely from diode to diode without causing any misliring or circuit failure. As a matter of fact, the use of the group diodes 104 through 143, in contrast with the prior art matrix which used resistors instead, results in no misring of the display diodes 72 through 102 as is true of said resistor matrix. Failure of proper operation occurs in the present invention only when a diode or neon lamp becomes completely defective, its characteristics changing far 'beyond the range normally encountered, or some other circuit failure occurs.

With respect to the resistors 71 through 101, typical values therefor may lie between 10,000-ohms and 100,000-ohms or more. These resistors serve to limit the current to safe values for the gas diodes. The resistors 72a, etc. of FIG. 3 may vary between 100,000-ohms to ZO-megohms. The value of the supply voltage is not critical, and depending upon circuit design may lie between 165 to 230 volts A.C. or 220 to 300 volts D.C. With respect to the circuits of FIGS. 1, 2 and 3, the power source 1l) may be either A.C. or D.C.; power source lila of FIG. 4 should be A.C.

While FIG. 6 indicates only a few letters, numerals and punctuation marks, it will appear as obvious to persons skilled in the art that the display panel of FIG. 5 and the associated circuit of FIGS. 1-4 inclusive may be used for obtaining an almost infinite variety of discrete character groupings without interfering with the inherent functioning of the circuitry. The same cannot be said for the prior art matrix which used resistors instead of diodes, since these resistors in the matrix network served to interconnect all of the matrix conductors, thereby consuming an inordinate amount of power. This 'being true, the resistance matrix was limited to use with a display panel capable of presenting only from 10 to l2 characters. This is in distinct contrast with the present invention which is capable of displaying, for example, the entire alphabet, numbers from 1 to 10, and several different punctuation marks as shown in FIG. 6, any one of these characters being instantly available for selection and presentation on the display panel from a common power source.

Since the diodes 104 through 143 are essentially open circuits until they are fired, the first and second conducf tors forming the matrix are, for all practical purposes, electrically isolated from each other. This is one reason why an almost infinite number of display characters may be achieved by use of a single matrix. Y

While only a few of the advantages inherent in this-invention have been mentioned, others will appear as obvious to persons skilled in the art.

What is claimed is:

1. An electrical control network comprising a plurality of iirst conductors, a plurality of switches each having open and closed positions, a power source having a pair of power supply lines, one each of said switches connecting a respective one Aeach of said iirstrconductors to one of said supply lines; a plurality of second conductors, a plurality of display neon lamps, a plurality of resistors, one each of said neon lamps being series-connected with a respective one each of said resistors to provide a plurality of lampresstor configurations, one each of said configurations being series-connected between a respective one each of said second conductors and the other of said supply lines; and a plurality of second neon lamps arranged in a plurality of different character groups, each group being composed of a plurality of said second neon lamps, said second neon lamps having first and second terminals, there being one group for each iirst conductor, the irst terminals of the lamps of each group being connected to the respective tirst conductor, and the second terminals of the lamps of each group being connected to preselected ones of said second conductors, predetermined ones of the second terminals of different groups being connected to predetermined common ones respectively of said second conductors, the arrangement being such that selective closing of any one of said switches respectively serially connects across said power supply lines the second lamps of the one group which have their first terminals connected to the first conductor to which said one switch is connected and the lamp-resistor configurations connected to the second conductors to which the second terminals of said one group of second lamps are connected thereby tiring the thus serially connected second lamps and display lamps whereby predetermined groups of said display lamps may be selectively energized by selective operation of said switches, all of the aforesaid neon lamps having a symmetrical switching characteristic and having substantially the same firing` and operating characteristics, said power source providing a voltage across said supply lines sufficient to fire two of said neon lamps in series but insufiicient to fire three of said neon lamps in series.

2. An electrical control network comprising a plurality of first conductors, a plurality of switches each having open and closed positions, a power source having a pair of power supply lines, one each of said switches connecting a respective one each of said first conductors to one of said supply lines; a plurality of second conductors, a plurality of display neon lamps, a plurality of resistors, one each of said neon lamps being series-connected with a respective one each of said resistors to provide a plurality of lamp-resistor configurations, one each of said configurations being series-connected between a respective one each of said second conductors and the other of said supply lines; and a plurality of second neon lamps arranged in a plurality of different character groups, each group being composed of a plurality of said second neon lamps, said second neon lamps having first and second terminals, there being one group for each rst conductor, the first terminals of the lamps of each group being connected to the respective first conductor, and the second terminals of the lamps of each group being connected to preselected ones of said second conductors, predetermined ones of the second terminals of different groups being connected to predetermined common ones respectively of said second conductors, the arrangement being such that selective closing of any one of said switches respectively serially connects across said power supply lines the second lamps of the one group which have their first terminals connected to the first conductor to which said one switch is connected and the lamp-resistor configurations connected to the second conductors to which the second terminals of said one group of second lamps are connected thereby firing the thus serially connected second lamps and display lamps whereby predetermined groups of said display lamps may be selectively energized by selective operation of said switches, all of said neon lamps having a symmetrical switching characteristic, said power source providing a voltage across said supply lines sufiicient to fire two of said neon lamps in series but insufficient to fire three of said neon lamps in series.

3. An electrical control network comprising a plurality of first conductors, a power source having two power supply lines, means for selectively connecting each of said first conductors with one of said supply lines and each having open and closed conditions; a plurality of second conductors, a plurality of display neon lamps, a plurality o resistors, one each of said neon lamps being series-connected with a respective one each of said resistors to provide a plurality of lamp-resistor configurations, one each of said configurations being series-connected between a respective one each of said second conductors and the other of said supply lines; and a plurality of second neon lamps arranged in a plurality of different character groups, each group being composed of a plurality of said second neon lamps, said second neon lamps having firstv and second terminals, there being one group for each first conductor, the first terminals of the lamps of each group being connected to the respective iirst conductor, and the second terminals of the lamps of each group being connected to preselected ones of said second conductors, the arrangement Ibeing such that selective closing of any one of said selective connecting means respectively serially connects across said power supply lines the second lamps of the one group which have their first terminals connected to the first conductor to which said one selective collecting means is connected and the lamp-resistor configurations connected to the second conductors to which the second terminals of said one group of second lamps are connected thereby firing the thus serially connected second lamps and display lamps where-u by predetermined groups of said display lamps may be se-v lectively energized by seiective connection of said first conductors to said one supply line, all of said neon lamps having a symmetrical switching characteristic, said power source providing a voltage across said supply lines sutiicient to fire two of said neon lamps in series but insufiicient to fire three of said neon lamps in series.

4. An electrical control network comprising a plurality of first conductors, a power source having two power supply lines, means for selectively connecting each of said first conductors withone of said supply lines and each having open and closed conditions; a plurality of second conductors, a plurality of electrically energizable devices, a plurality of resistors, one each of said devices being series-connected with a respective one of each of said resistors to provide a plurality of device-resistor'configurations; one each of said configurations being seriesconnected between a respective one each of said second conductors and the other of said supply lines; and a plurality of neon lamps arranged in a plurality of different character groups, each group composed of a plurality of neon lamps having first and second terminals, there being one group for each first conductor, the first terminals of the lamps of each group being connected to the respective first conductor, and the second terminals of the lamps of each group Vbeing connected to preselected ones of said second conductors, the arrangement being such that selective closing of any one of said selective connecting means serially connects across said power supply lines the lamps of the one group which have their first terminals connected to the first conductor to which said one selective connecting means is connected and the device-resistor configurations connected to the conductors to which the second terminals of said one group of lamps are connected thereby respectively firing and energizing the thus serially connected lamps and devices whereby predetermined groups of said devices may be selectively energized by selective connection of said first conductors to said one supply line, all of said neon lamps having a symmetrical switching characteristic, said power source providing a voltage across said power supply line sufiicient to fire one neon lamp in series with a said device but insufiicient to fire two neon lamps in series with a said device.

5. An electrical control network comprising a plurality of rst conductors, a power source having two power supply lines, means for selectively connecting each of said first conductors with one of said supply lines and having open and closed conditions; a plurality of second conductors, a plurality of electrically energizable devices, one each of said devices being series-connected `between a respective one each of said second conductors and the other of said supply lines; and a plurality of neon lamps arranged in a plurality of different character groups, each group composed of a plurality of neon lamps having first and second terminals, there being one group for each first conductor, the first terminals of the lamps of each group being connected to the respective first conductor, and the second terminals of the lamps of each group being connected to preselected ones of said second conductors, predetermined ones of the second terminals of different groups being connected to predetermined common ones respectively of said second conductors, the arrangement being such that selective closing of any one of said selective connecting means serially connects across said power supply lines the lamps of the one group which have their first terminals connected to the iirst conductor to which said one selective connecting means is connected and the device-resistor configurations connected to the conductors to which the second terminals of said one group of lamps are connected thereby respectively firing and energizing the thus serially connected lamps and devices whereby predetermined groups of said devices may be selectively energized by selective connection of said first conductors to said one supply line,l all of said neon lamps having a symmetrical switching characteristic, said power source providing a voltage across said power supply line suicient to rire one neon lamp in series with a said device but insuflicient to iire two neon lamps in series with a said device.

6. An electrical control network comprising a plurality of first conductors, a power source having two power supply lines, means for selectively connecting cach of said first conductors with one of said supply lines and having open and closed conditions; a plurality of second conductors, a plurality of electrically energizable devices, one each of said devices being series-connected between a respective one each of said second conductors and the other of said supply lines; a plurality of gaseous discharge diode devices arranged in a plurality of diierent character groups, each group composed of a plurality of said gaseous devices, said gaseous devices having first and second terminals, there being one group for each lirst conductor, the rst terminals of the gaseous devices of each group being connected to the respective first conductor, and the second terminals of the gaseous devices of each group being connected to preselected ones of said second conductors, the arrangement being such that selective closing of any one of said selective connecting means respectively serially connects across said power supply lines the diode devices of the one group which have their first terminals connected to the first conductor to which said one selective connecting means is connected and the electrically energizable devices connected to the second conductors to which the second terminals of said one group of diode devices are connected thereby respectively ring and energizing the thus serially connected diode devices and electrical energizable devices whereby predetermined groups of said energizable devices may be selectively energized by selective connection of said first conductors to said one supply line, all of said diode devices having a symmetrical switching characteristic, said power source providing a voltage across said lines sufiicient to fire one said diode device in series with an electrically energizable device but insucient to iire two diode devices in series with an electrically energizable device.

7. An electrical control network comprising a plurality of first conductors, a power source having two power supply lines, means for selectively connecting each of said first conductors with one of said supply lines and each having open and closed conditions; a plurality of second conductors, a plurality of electrically energizable devices, one each of said devices being series-connected between a respective one each of said second conductors and the other of said supply lines; a plurality of static-switching devices arranged in a plurality of diierent character groups, each of said devices having a high impedance when off and being turned on responsive to application of a predetermined voltage, each group bein-g composed of at least one of said static-switching devices, said static-switching devices each having first and second terminals, there being one group for each first conductor, the rst terminals of the static-switching devices of each group being connected to the respective rst conductor, and the second terminals of the static-switching devices of each group being connected to preselected ones of said second conductors, predetermined ones of the second terminals of different groups being connected to predetermined common ones respectively of said second conductors, the arrangement being such that selective closing of any one of said selective connecting means respectively serially connects across said power supply lines the static-switching devices of the one group which have their first terminals connected to the first conductor to which the said one selective connecting means is connected and the electrically energizable devices connected to the second conductors to which the second terminals of said one group of static-switching devices are connected thereby respectively turning on and energizing the thus serially connected static-switching devices and electrically energizable del0 vices whereby predetermined groups of said energizable devices may be selectively energized by selective connection of said first conductors to said one supply line, said power source providing a voltage across said lines sufficient to turn on one of said switching devices in series with an electrically energizable device but insufficient to turn on two of said switching devices in series with an electrically energizable device.

8. The network of claim 6 wherein said electrically energizable devices are respectively one winding of transformers.

9. An electrical control network comprising a plurality of lirst conductors, a power source having two power supply lines, means for selectively connecting each of said first conductors with one of said supply lines and each having open and closed conditions; a plurality of second conductors, a plurality of display neon lamps, a plurality of resistors, one each of said neon lamps being seriesconnected with a respective one each of said resistors to provide a plurality of lamp-resistor configurations, one each of said configurations being series-connected between a respective one each of said second conductors and the other of said supply lines; `a plurality of thyratrons having anode, control grid and cathode elements, respectively, the control grid and cathode elements of one thyratron being connected across a respective one of said resistors, means including said resistors for tiring said thyratrons when a predetermined current passes through a respective resistor; and a plurality of second neon lamps arranged in a plurality of different character groups, each group being composed of a plurality of said second neon lamps, said second neon lamps having first and second terminals, there being one group for each first conductor, the first terminals of the lamps of each group being connected to the lrespective rst conductor, and the second terminals of the lamps of each group being connected to preselected ones of said second conductors, the arrangement being such that selective closing of any one of said selective connecting means respectively serially connects across said power supply lines the second lamps of the one group which have the fhst terminals connected to the iirst conductor to which said one selective connecting means is connected and the lampresistor configurations connected to the second conductors to which the second terminals of said one group of second lamps are connected thereby firing the thus serially connected second lamps and display lamps and causing firing of the respective thyratrons whereby predetermined groups of said display lamps may be selectively energized by selective connections of said first conductors to said one supply line, said power source providing a voltage across said supply lines suflicient to iire a thyratron and two neon lamps in series with the respective resistor, but

insufficient to re a thyratron and three neon lamps in series with a respective resistor.

l0. An electrical control network comprising a plurality of lirst conductors, a power source having two power supply lines, means for selectively connecting each of said yfirst conductors with one of said supply lines and each having open and closed conditions; a plurality of second conductors, a plurality of electrically energizable devices, one each of said devices being series-connected between a respective one each of said second conductors and the other of said supply lines; a plurality of staticswitching devices arranged in a plurality of dilerent character groups, each of said switching devices having -a high impedance when off and being turned on responsive to application of a predetermined voltage, each group composed of at least one of said static-switching devices, said st-atic-switching devices each having iirst and second terminals, there being one group for each first conductor, the first terminals of the static-switching devices of each group being connected to the respective rst conductor, and the second terminals of the static-switching devices of each group being connected to preselected ones of said second conductors, predetermined ones of Athe second terminals of different groups being connected to predetermined common ones respectively of said second conductors, the arrangement being such that selective closL ing of yany one of said selective connecting means frespec tively serially connects across said power supply lines the static-switching devices of the one group 'which have their first terminals connected to the first conductor to which the said one selective connecting means is connected and the electrically energizable devices connected to the second conductors to which the second terminals in said one group of static-switching devices are connected thereby respectively turning on and energizing the thus serially connected static-switching devices and electrically energizable devices whereby predetermined groups of said energizable devices may be selectively energized by selective connection of said rst conductors to said one supply line, and means responsive to the selective connection of said rst conductors to said one supply line for maintaining said energizable devices energized, said source providing a voltage across said supply lines sufcient to 12 turn on one of said switching devices in series with one electrically energizable device but insucient to turn on two of said switching devices in series with one electrically ener-gizable device.

References Cited in the file of this patent UNITED STATES PATENTS 1,769,060 Hendry July '1, 1930 2,049,763 De Forest Aug. 4, 1936 2,056,661 Foulke Oct. 6, 1936 2,136,441 Kaious ,Nov. 15, 1938 2,142,106 Boswau Jan. 3, 1939 2,292,064 Dorgelo et al. Aug. 4, 1942 2,603,716 Low July 15, 1952 2,738,499 sprick Mar. 13, 1956 2,862,660 Purcell Dec. 2, 1958 2,889,538 Geisler June 2, 1959 2,918,608 Rieth Dec. 22, 1959 FOREGN PATENTS 684,055 Great Britain Dec. 10, 1952 

